1. Field of the Invention
The present invention relates to an antenna system and a television receiver.
2. Description of the Related Art
Conventionally, an antenna that is capable to switch directional property (what is called “smart antenna”) when receiving a television broadcast signal (hereinafter referred to as “TV broadcast signal”), has been known.
Specifically, such antenna is capable to switch the directional property by control from an antenna system (receiving apparatus) in accordance with a predetermined standard such as EIA/CEA-909 or the like, for example.
An antenna system including such antenna decides optimal receiving direction of the antenna for each channel at initial settings. Then, in a case where a desired channel is assigned by a user during ordinary operation, the antenna system switches directional property of antenna to an optimal receiving direction that corresponds to the desired channel which is decided at initial settings, and receives TV broadcast signal that corresponds to the desired channel.
Concerning the antenna system as afore-mentioned, in order to receive TV broadcast signal with high quality, an antenna system that extracts a preferable directional property in which quality of received signal of the TV broadcast signal received by the antenna is not less than a threshold value during ordinary operation, and switches directional property of the antenna to the preferable directional property which is extracted (For example, refer to Japanese Patent Specification (Laid Open) No. 2005-217848), has been suggested.
Further, concerning an antenna system that has a plurality of antennas that are not capable to switch directional property, in order to receive TV broadcast signal with high quality, an antenna system that switches to other preferable antenna so that the quality of received signal is not less than the threshold value, in a case where the quality of received signal of the TV broadcast signal received by one antenna is lower than the threshold value during ordinary operation (For example, refer to Japanese Patent Specification (Laid Open) No. 2005-217849), has been suggested.